Vintage Tractor Engineer

This is a guest post from Alan Clark…

Here is a detailed explanation of the reason a Series Wound starter motor still rotates the same way regardless of battery polarity.

When Battery Polarity is reversed both Field and Armature currents are reversed [Because it is Series wound]-rotation direction remains the same.

If the Starter were to be dismantled and either the field or the armature connections reversed the Starter rotation would reverse

If you have any tractor related mechanical articles that would be useful to our community then please contact us.  It is good to pass on tractor knowledge.

In the UK we’ve had two consecutive cold winters and the frost has blown core plugs from some engines which haven’t either been drained of coolant or had sufficient antifreeze concentrations.  Owners who have had blown core plugs are lucky that this fail-safe has worked – they could have been dealing with a more serious (and expensive) cracked block.  This highlights the need to prepare your tractor for winter.

How To Fit Core Plugs

There are different designs of core plug for different engines.  The task is quite straight forward on the Perkins engines, as the plugs are simply hammered into position with a suitable drift and light hammering.

23C Engine

The design of the core plug and fitting method for the Standard 23C engine is somewhat different.

Here are the core plug fitting instructions…

On these engines the new core plugs are a convex shape (like a dish shape). You clean the hole out and put some sealant around the edge of the hole (something like ‘Instant Gasket’ or ‘Loctite Flange Sealant’).  The sealant isn’t technically necessary (as eventually any leak would seal with rust), but it is better for an immediate seal.

Next get the new core plug and place the lip of the plug into the hole (so if you imagine something such as a breakfast bowl, the bottom of the bowl needs to be facing towards you to the outside of the engine block) and then using a suitably shaped wide punch you hit the centre of the core plug until it starts to flatten out.  This expands the outer rim of the plug and makes a water tight seal.  The plug needs to be nearly flat, but NOT flat.  If you  get it to the point of been flat then it will loose its grip and it will just fall out.

It is sometimes possible to re-use an old core plug if you are able to re-form the dish shape prior to fitting the plug.

Here at Vintage Tractor Engineer we are used to working with the UK built Ferguson tractors.  However, when it comes to some of the US built machines we start to get a bit lost as to which model is the UK equivalent and are they exactly the same or just very similar with small differences.

Then we get emails about the French built tractors and we get lost altogether!

MF835

We had a gentleman who needed information about the injection pump on his MF835.  Apparently the pump is a Lavalette Brevete.

We’ve now been given the link to a French site that has information on these pumps…

http://vieilles.soupapes.free.fr/index.php

Unfortunately Vintage Tractor Engineer’s French is about as much use as engine that’s done 15,000 hours and never had its oil changed!  Anyway, apparently the information is on that website somewhere.

If you need to translate anything then Google Translate seems to work quite well.

What is the ring gap?

We can see the unworn portion on this liner.  The photo doesn’t show it well, but the cross hatching is visible.

What are the ring gap tolerances?

For original Ferguson/MF rings and liners…

Top ring gap  9 to 17 thou

Second and third ring gaps 9 to 14 thou

New rings out of specification

We have had a few people email us to say that they have got new pistons, rings and liners and that they have measured them before fitting and found that they are out of spec.

These have all been manufactured by a non-genuine parts supply company and unfortunately some of these companies seem not to be able to manufacture parts to the necessary accuracy.

Typically the following ring gaps have been measured from these parts suppliers…

Top ring gap 23 thou

Second and third ring gaps 18 thou

Oil ring 15 thou

What to do?

Firstly measure either your tool or (more likely) the liner you are using to measure the ring gap in.  Check it is within spec.  If it is within spec and you are experiencing ring gaps which are too large then compression is likely to be compromised.

Ideally these ‘new’ components should be rejected and replacement parts sourced from another manufacturer.

Daryle has emailed to offer this tip…

Excellent advice on Liners, if I may offer a tip, is to keep your liners standing. Laying them on their side will often distort them.

Thanks Daryle, much appreciated – Steve and Ian.

We are always getting requests for different tractor mainenance DVD’s, tutorials or guides on how to do different jobs.  This one came in recently…

Hello, I have the 23C Engine Rebuild & MF 35 Hydraulics Repair DVDs, they’re great. Any chance you could do one for the 20C engine, the TE20/MF35/MF135 G/boxes including Multi Power? I really enjoy the intelligent pace of the videos… Ian instructs very well and assumes correctly the level / ability of his audience… his style really suits me anyway! Best Regards, John S.

Well John,

Thanks for your kind message about the previous DVD’s you have purchased from us. I am glad you have enjoyed watching them and found them useful.

We have a 20C engine waiting to be done at the moment, but another tractor has just come in from a customer (MF 35 3 cylinder Perkins) so we are going to film that one first. The 20C DVD will come eventually, but I don’t just know how long it will be before we get it done.

As for the gearboxes – Well on the whole they are just so reliable that we didn’t think we’d sell hardly any DVD’s for gearbox refurbishment. Obviously the multi-power is the exception to this rule and so that may be the place to start with gearboxes.

We get lots and lots of requests for different DVD’s or guides on how to refurbish rear axles, steering boxes, brakes, alternator, wiring, etc. etc. As time goes on we hope to make all these tutorials available for MF35, TE20 and then the 100 series tractors and also probably eventually the 500 series (as people are starting to collect and restore the 500’s as well now). So much to do and so little time!

Many thanks for your requests. If you keep an eye on the website then no doubt all these things will become added in the future. There is a subscribe button on the website, if you enter your email address into the box the system will email you whenever a new page is posted up so it is then easy to keep up to date with what is happening.

We’re working as fast as we can!

Anyone who reads Vintage Tractor Engineer regularly will know that we just love tractors here.  Local repairs  is our business and then we make the DVD’s and post up the little tips and tutorials on the website so that tractor enthusiasts all over the world can get help and advice.

We like what we do here at VTE and enjoy the contact with customers.

We hope everyone gets useful information from the site and the videos and we will slowly add more and more tutorials as we go along.

Steve and Ian.